For soft tissue sarcoma patients receiving preoperative radiation therapy, wound complications are common and potentially devastating; they may result in multiple subsequent surgeries and significant patient morbidity. The purpose of this study was to assess the feasibility of intraoperative indocyanine green fluorescent angiography (ICGA) as a predictor of wound complications in resections of irradiated soft tissue sarcoma of the extremities.

A consecutive series of patients of patients with soft tissue sarcoma of the extremities or pelvis who received neoadjuvant radiation and a subsequent radical resection received intraoperative ICGA with the SPY PHI device (Stryker Inc, Kalamazoo MI) at the time of closure. Three fellowship trained Orthopaedic Oncologic Surgeons were asked to prospectively predict likelihood of wound complications based on fluorescence. Retrospective analysis of fluorescence signal along multiple points of the wound length was performed and quantified. The primary endpoint was wound complication, defined as delayed wound healing or wound dehiscence, within 3 months of surgery. An a priori power analysis demonstrated that 5 patients were necessary to achieve statistical significance. Univariate and multivariate statistical analyses were performed to identify predictors of wound complications.

14 patients were consecutively imaged. The diagnosis was undifferentiated pleomorphic sarcoma in 9 (64.3%) of patients; 11 (78.6%) tumors were high grade. There were 6 patients with wound complications classified as “aseptic” in 5 cases and secondary to hematoma in 1 case. Using the ICGA, blinded surgeons correctly predicted wound complications in 75% of cases. In the area of wound complication, the mean % of maximal signal for wound complications was 49% during the inflow phase and 48% during the peak phase. The mean % maximal signal for peri-incisional tissue without wound complications was 77% during the inflow phase and 83% during the peak phase (p=0.003 and p<0.001). During the inflow phase, a mean ratio of normal of 0.62 maximized the area under the curve (AUC=0.90) for predicting wound complications with a sensitivity of 100% and specificity of 77.4%. During the peak phase, a mean ratio of normal of 0.55 maximized the area under the curve (AUC=0.95) for predicting wound complications with a sensitivity of 88.9% and a specificity 100%.

Intraoperative use of indocyanine green fluorescent angiography may help to predict wound complications in patients undergoing resection of preoperatively irradiated soft tissue sarcomas of the extremities and pelvis. Future studies are necessary to validate this technology in a prospective manner and to determine if interventions can be instituted to prevent predicted wound complications.